Recovery of iron and other metal compounds from polluted filter residue/sand emanating from drinking and process water processes for use in color provision in brick and concrete block manufacture

摘要

Iron and other metal compounds are recovered from polluted filter residue/sand emanating from drinking and process water processes for use in color provision in brick and concrete block manufacture. An eddy bed (2) is operated as a continuous process, starting with cleaned filter residue or contaminated filter residue. Contaminated filter residue is fed (1) continuously or semi-continuously. The bed height is monitored using difference pressure meters and when the specified bed height is reached a part of the bed material is tapped off (3). The removal of iron particles from the air or gas flow is effected with a cyclone (4) followed by a sheet filter (5). The gas flow after leaving the cyclone and before the sheet filter is cooled by a heat exchanger (6). The heat can be used for heating the ingoing air or gas flow (7).